Photo-electric detonator controlled by searchlight



Oct. 1, 1935. J. H. HAMMOND, JR

PHOTO ELECTRIC DET ONATOR CONTROLLED BY SEARCHLIGHT Filed Jan. 5', 1954 2 Sheets-Sheet J,

N1E= T Oct. 1, 1935.

.1. H. HAMMOND; J

PHOTO ELECTRIC DETONATOR CONTROLLED BY SEARCHLIGHT Filed Jan. 5, 1954 Z'SheetS-SheQt 2 IIIIIIIIII I! Patented Oct. 1, 1935 PHOTO-ELECTRIC DETONATOR CON- TROLLED BY SEARCHLIGHT John Hays Hammond, Jr., Gloucester, Mass.

Application January 5, 1934, Serial No. 705,356

10 Claims.

This invention relates to ordnance devices and more particularly to torpedoes.

According to one form of invention, a torpedo may be provided with a light sensitive device 6 which controls the detonation of the explosive charge thereof when it passes beneath a ship. The torpedo mechanism may include a photoelectric cell which is energized by a source a light external to the torpedo, the light being trans- 10 mitted through the water above the torpedo. When the torpedo passes beneath a ship, the shadow causes the deenergization of the photoelectric cell which in turn may be arranged to cause the detonation of the war head of the to'r- 15 pedo. The external light source, according to one form of the invention, may be located on the firing vessel.

The invention may also provide a means whereby the detonation of the war head of the torpedo 20 is delayed a predetermined time after the photosensitive means has passed into the shadow of the ship in order to allow the explosion to occur near the central portion of the vessel, where it would be most efiective rather than at the so 25 called blister where it would be comparatively inefiective.

The invention also consists in certain new and original features of construction and combinations of parts hereinafter set forth and. claimed.

30 Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, the mode of its operation and the 35 manner of its organization may be bette r understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which Fig. 1 represents diagrammatically the forward portion of a torpedo provided with this invention.

Fig. 2 diagrammatically illustrates the course of a torpedo attacking an enemy vessel.

Fig. 3 illustrates diagrammatically the source of illumination external to the torpedo.

Fig. 4 is a front viewof part of the apparatus shown in Fig. 3, and

Fig. 5 is a modified form of the apparatus shown 50 in Fi 3. I

Like reference characters denote like parts in the several figures of the drawings.

In the following description and in the claims, parts will be identified by specific names for con- 55 venience, but they are intended to be as generic in their application to similar parts as the art will permit.

Referring to the accompanying drawings, and more particularly to Figure 1, there is shown a waterborne body such as a carrier of explosives .5. having a water tight torpedo hull l0, and arranged to be propelled in the usual manner by propellers located at the after end. The hull I0 is provided with two transverse bulkheads II and 2, thus providing two compartments 3 and I4, the former being filled with an explosive charge I 5, such for example as T. N. T.

. A hole is provided in the hull H1 at the top of the compartment 4. This hole is covered by a sheet of glass or other transparent material l6. Mounted in a tube I1 is a lens l8 which is positioned directly below the hole in the hull. The interior of the tube I1 is painted a fiat black so as not to reflect any light. Positioned at the focus of the lens I8 is a photoelectric cell I9 which is connected in the input circuit of an amplifier 20.

A clock-work mechanism 2| is provided which drives a commutator 22. This commutator is provided with a conducting segment 23. To the shaft of the commutator is secured an arm 25. which normally engages a pin 26. A second pin 21 is provided for limiting the motion of the arm 25 and the commutator 22.

Engaging the commutator 22 are four brushes 28, 29, and 3|. The brush 28 is connected to 30 one side of the output circuit of the amplifier 20. The brush 29 is connected to one side of a solenoid 32, the other side of which is connected to the other side of the amplifier 20.

The solenoid 32 is provided with a core 36 which is adapted to be moved to the left as shown in Fig. 1 when this solenoid is energized. Secured to one end of this core is a piston 31 which reciprocates in a cylinder 38. This cylinder is provided with a port 39 covered by a flap valve 40 40 which is adapted to allow the air to escape rapidly from this cylinder. The cylinder is also provided with a port 4 I. the opening in which is controlled by a needle valve 42 for restricting the flow of air through this port. 45

To the other end of the core 36 is secured an insulating member 45 between which and the solenoid 32 is mounted a compression spring 46. Mounted on the insulating member 45 is a contact 41 which is connected to the contact 3| and .at suitable times engages a conducting segment -48 mounted on an insulating base 49. The seg ment 48 is connected to one side of a detonator 50, the other side of which is connected to the contact 30 through a battery 5|. v

For automatically starting the clock-work mechanism 2| a heavy weight II is secured to the end of a flat spring I2 the upper end of which is fastened to the casing of the clock-work mechanism 2|. The weight II is provided with a projection I3 which normally engages a finger '14 which controls the starting of the clock-work mechanism. Engaging the end of the finger I4 is a spring I5 which is supported on a bracket I8.

In the operation of this system when the torpedo is fired the inertia of the weight M causes it to be moved backward relative to the torpedo thus disengaging the projection I3 from the finger I4 which is moved upwardly under the action of the spring I5 thus causing the clockwork mechanism to start turning the commutator 22 at a predetermined speed. After a predetermined interval of time the segment 23 of the commutator 22 will engage the brushes 28 and 29 thus connecting the amplifier 20 to the solenoid 32 which will be energized, as the photoelectric cell will by this time be receiving light, focused upon it by means of the lens I8 from an external source presently to be described. This will cause the core 36 of the solenoid 32 to be moved rapidly to the left as the air in the cylinder 38 is freely exhausted through the port 39. The contact 41 moves off of the segm'ent 48 thus keeping the circuit to the detonator 50 open when the commutator segment 23 engages brushes 30 and 3|.

This condition continues as long as the photoelectric cell I9 receives light through the lens I8. When the torpedo passes beneath an enemy ship, however, the light will be cut ofi from the photoelectric cell I9 thus causing the deenergization of the solenoid 32. The deenergization of the solenoid 32 allows the core 36 to be moved slowly to the right under the action of the spring 46, the speed of this motion being determined by the setting of the needle valve 42. After a predetermined interval of time the contact 41 will engage the segment 48 thus closing a circuit from the battery 5| through the segment 23 and contact 41 to the detonator 50 which is detonated thereby exploding the charge-of explosive I5 in the war head of the torpedo.

This explosion will take place directly under the center of the ship and in contact with the hull as the mechanism has been so timed that it will give the torpedo a sufficient time to reach a position under the center of the ship and the horizontal rudders will have directed the torpedo upwardly so that it is in contact with the hull of the ship.

Any suitable source of light may be used for illuminating the torpedo during its run such.as a searchlight 8I mounted on a vessel 82. This searchlight produces a beam indicated at 83 which illuminates the target such as an enemy ship 84 and also the surface of the water between the vessel 82 and the enemy 84 as indicated at 85. The light striking the surface of the water in this area is diffused downwardly by refraction as indicated at 86 and illuminates the photoelectric cell I 9 in the torpedo as it traverses this area. When the torpedo passes into the shadow 81 of the ship 84 the illumination of the photoelectric cell will be decreased thus causing the explosion of the war head as already described.

In order that the searchlight may not be used for a longer time than is absolutely necessary, a timing device 9| is provided on the vessel 82. This device is essentially similar in construction to the clock-work mechanism 2I on the torpedo and is provided with the commutator 92 which is rotated at the same speed as the commutator 22. The commutator 92 carries a conducting segment 93 which after the lapse of a predetermined interval of time engages two contacts 94 and 95 which control the circuit of the searchlight 8I. The starting mechanism for the timing device 9i is controlled by a solenoid 96 which when energized releases a trip 91 which starts the clockwork mechanism in operation. The solenoid 9B is energized by a battery 98 and controlled by a key 99 which is preferably located adjacent to the torpedo firing mechanism so that it is closed at the same instant that the torpedo is fired.

In this way the torpedo travels during most of its course without being illuminated, but as it approaches the enemy the segment 93 of the timing device 9| will engage the contacts 94 and 95 thus illuminating the searchlight BI. A brief interval after this the conducting segment 23 of the clock-work mechanism 2| will engage the contacts 28 and 29 thereby energizing the solenoid 32 as already described by the light shining on the photoelectric cell I9.

It is thus seen that after the torpedo is fired it will travel to the proximity of the enemy, then the searchlight will be automatically switched on and a few seconds later the photoelectric controlled mechanism in the torpedo will be made operative and will continue so until the torpedo passes beneath the enemy ship at which time the explosive charge will be detonated.

In order to make the system selective so that the torpedo cannot be controlled by the enemy a means for producing predetermined periodicity of the light beam is provided, such for example as a rotating disc shutter I00 which is carried on the shaft of a motor IOI this motor being energized from a battery I02 and controlled by a switch I03. The disc I00 is provided with openings I04 so that as it rotates it periodically occults the light beam thus producing a frequency which is dependent upon the speed of the motor and the number of openings I04. In this case the amplifier will be tuned to the same frequency as the light beam so that it will only be responsive to light of this frequency.

A modified form of producing the frequency desired is shown in Fig. 5 in which the supply of current to the searchlight 8I passes through the secondary of transformer I05 the primary of which is energized by a pulsating current such as that produced byan alternator I06. The supply of this current is controlled by a switch I01. This causes a pulsation of the light of thesearchlight with a frequency equal to that of the alternator I06 and in this case the amplifier 20 must be tuned to this same frequency in order to make the system selective.

In order to prevent the premature explosion of the torpedo in the event that it should pass under some floating dbris and thereby momentarily occult the light sensitive means, any type of well-known delay action circuit may be incorporated in the amplifier 20, so as to make it necessary for the photoelectric cell I9 to be occulted for an appreciable length of time before the operation of the mechanism will be initiated.

An important advantage of. this system of running torpedoes at considerably greater depths than are now used is the fact that at these depths the wakes are much farther. behind the torpedoes when they come to the surface due to the longer time it takes the bubbles of air to rise to the surface and that the wakes are much less conspicuous due to the fact that the air has had a longer time to become diffused in the water. It is, therefore, much more diflicult to observe and locate these torpedoes than those run at present-day depths.

The photoelectric cell l9 may be of the new type developed by the Weston Instrument Company and the Westinghouse Electric and Manufacturing Company in which case the amplifier 20 may be replaced by a, sensitive tuned relay, which controls the circuits of the solenoid 32. These new cells generate sufiicient current to operate a sensitive relay directly without the use of an amplifier or a battery. A condenser may be shunted across the relay or any other well known device may be employed to delay the operation of the relay, so that the mechanism will not be operated by a momentary occultation of the photoelectric cell, such as would be caused by the torpedo passing under floating dbris. The tuned relay may be of any well-known construction such as the vibrating reed type and is tuned to the frequency of the light source.

Although only a few of the various forms in which this invention may be embodied have been shown herein, it is to be understood that the inventionis not limited to any specific constructions, but might be embodied in various forms without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1. In combination a moving bodyhaving an explosive charge, an external source of artificial light of predetermined characteristics, means for detonating said charge, and a light sensitive device for operating said detonating means when illuminated with light fromsaid source so that when the illumination on said device is changed it will cause the detonation of said explosive charge and means for preventing the detonation of said explosive charge for a predetermined time after the launching of said body.

2. In combination, a moving body having an explosive charge, an external source of artificial light of predetermined characteristics, means for detonating said charge, a light sensitive device for operating said detonating means controlled by light from said source so that when the illumination on said device is changed it will cause the detonation of said explosive charge and means for preventing the detonation of said explosive charge for a predetermined time after the illumination on the light sensitive device has been changed.

3. In combination with a moving body, an external source of artificial light, an explosive charge, means for causing the detonation of said charge and light sensitive means for controlling said detonating means controlled by light from said source so that at a predetermined interval after the intensity of illumination of said light sensitive means is changed it will cause the de tonation of said explosive charge.

4. Ina system for controlling moving bodies an external source of illumination having predetermined characteristics, a moving body provided with an explosive charge, means carried by said body for receiving light from said source 5 and tuned to said characteristics, and means operated by the change of intensity of said light for causing the detonation of said.explosive charge.

5. In a system for controlling moving bodies, an external source of illumination, means for controlling said illumination so that itwill not be efiective until the lapse of a predetermined interval of time, a moving body provided with an explosive charge, means carried by said body for receiving light from said source of illuminaton, means for controlling said light sensitive means so that it will not be efiective until a predetermined intervalof time has elapsed, and means operated by the change of intensity of said light for causing the detonation of said explosive.

6. In combination with a moving body, an external source of artificial light, an explosive charge carried by said moving body, light receptive means mounted on said body for receiving artificial light from said external source, and

means operated by said light receptive means for detonating said explosive charge when the intensity of illumination is changed. 7. In a system for controlling moving bodies,

'an' external source of artificial illumination, a

moving body provided with an explosive charge, means carried by said body for receiving light from said source, and means operated by the change of intensity of said light for causing the detonation of saidexplosive charge.

8. In a torpedo detonating system, a torpedo, an explosive charge carried thereby, a vessel, a source of light on said vessel, a device in said 40 torpedo sensitive to light from said source, and means responsive to a change in intensity of light received by said device to detonate said charge.

9. The method of maneuvering a torpedo 5 which comprises running the torpedo at a substantial depth below the surface of the water, projecting a beam of light from a pointabove the surface onto an enemy ship and the water surrounding said ship, receiving said light on said torpedo, and causing the cessation of light resulting from the passing of said torpedo under said enemy ship to initiate the detonation of the explosive charge carried by said torpedo.

10. The method of maneuvering a torpedo which comprises firing the torpedo, running said torpedo at a substantial depth .below .the surface of the water, projecting a beam of light from the firing ship, receiving the light in a light-sensitive device on said torpedo, and detonating the explosive charge on said torpedo responsive to a cessation of said light.

JOHN HAYS HAMMOND, JR. 

